Catamaran power boat

ABSTRACT

A catamaran power boat has two spaced apart hulls interconnected by a substantially flat deck. Straddle-type pedestal seating is provided along the fore and aft center line of the deck with a handlebar-type steering mechanism located at the forward portion of the seating facility. Each hull has a substantially vertical step located approximately one-third of the distance from the aft portion of same. Hydraulic controls operate trim tabs to help the vessel regain a planing attitude during the various stages of the operation thereof.

U n ite States Patent Paul A. Rings Kansas City;

Robert P. Kaufiman, J r.; Edward F. Kroil, both of Grandview, all of,Mo.

Aug. 4, 1969 June 1 5 197 l Skipper Nautical Corporation Grandview, Mo.

Inventors Appl. No. Filed Patented Assignee CATAMARAN POWER BOAT 10Claims, 10 Drawing Figs.

U.S. Cl 114/665,

114/61, 115/70 Int. Cl 1363b 1/22 Field of Search 114/665 P,

[56] References Cited UNITEQ STATES PATENTS 3,294,055 12/1966 McGuire115/70 3,373,715 3/1968 Stacey 1. [15/70 Primary Examiner-Andrew H.Farrell Attorney-Sc0field, Kokjer, Scofield and Lowe ABSTRACT: Acatamaran power boat has two spaced apart hulls interconnected by asubstantially flat deck. straddle-type pedestal seating is providedalong the fore and aft center line of the deck with a handlebar-typesteering mechanism located at the forward portion of the seatingfacility.

Each hull has a substantially vertical step located approximatelyone-third of the distance from the aft portion of same. Hydrauliccontrols operate trim tabs to help the vessel regain a planing attitudeduring the various stages of the operation thereof.

PATENTEDJUNISIHYI 3,584,590

SHEET 1 OF 2 INVENTOR 441% A RNEYS CATAMARAN POWER BOAT BRIEFDESCRIPTION OF THE INVENTION The basic catamaran structure has long beenrecognized as being synonymous with sail boat stability. For example,monohull crafts have utilized an outrigger concept to provide stabilitywithout significantly decreasing the mobility of the vessel utilizingsame. Our invention makes use of the heretofore known advantages of thecatamaran, yet, includes several improvements which are effectivelycombined to result in a highly efficient, low priced, safe, sturdy,durable and easily transportable power boat having all of the advantagesof the catamaran concept.

With the tremendous increase in popularity in power boating and waterskiing, a need was quickly established for a safe, maneuverable andinexpensive craft which was capable of towing a number of skiers andcomfortably and conveniently accommodating a number of passengers andrelated gear, yet be operable with a minimum ofpower source.

Our catamaran power boat has two spaced apart parallel hulls which areintegrally formed or connected with a substantially flat deck at theupper end extremities thereof. Each hull has a substantially verticalstep formed therein at a location which is approximately one-third ofthe overall length from the aft portion of the boat. A keel plate islocated at each hull step to add stability in making turns and tomaintain a steady course with minimum drift. I

The upper portion of the deck has straddle pedestal-type seatingfacilities with a rear swivel seat for skier monitoring. Handlebar-typesteering means are located on the forward portion of the seatingfacility with the operating console in easy reach of the operator. Therear portion of the deck includes a motor well which will accommodatethe motor as it is tilted forward and/or associated with fuel lines andtanks.

The underside of our catamaran power boat includes the above-mentionedtwo parallel hulls with the keel portion occupying the area described bythe longitudinal center line of each hull. A motor fairing is locatedimmediately forward of the motor position and protects the motor fromthe normal turbulence created by the boat moving through the water athigh speeds.

Finally, the boat is equipped with a unique steering mechanism andfold-out ladder facility, both of which significantly increase theusability of our boat.

It is an object of our invention to provide a uniquely constructed powerboat that is safe, extremely stable at high speeds, and which isconvenient for the operator and passengers alike.

Another object of the invention is to provide a power boat of thecharacter described which includes a means for causing the boat toassume the proper planing attitude in an optimum time period whilepulling skiers up out of the water. It is an important feature of ourinvention that the total resistance to boat propulsion is reduced by thehull construction and assisted by the causing means described above.

Another object of the invention is to provide a catamaran power boathaving uniquely constructed parallel hulls. It is a feature of ourinvention that the hulls include a vertical step with a keel platelocated thereat to prevent slipping while making turns and maintaining asteady course with minimum drift. We have further found that thevertical step in each hull at approximately one-third the distance fromthe aft portion of the boat provides for optimum planing of the boatduring operation.

A further object of the inventionis to provide a catamaran power boatthat includes a motor fairing located on the underside of the motor wellportion of same and which operates to break up water turbulence and toprotect the motor during normal and high-speed operations thereof.

A still further object of the invention is to provide trim tabs on apowered catamaran with hydraulic controls, therefore, it is a feature ofthe invention that the trim tabs have three operative positions and istotally controlled by a foot pedal and hydraulic circuit to optimallyutilize the hull construction.

Another object of the invention is to provide a unique steeringmechanism for a powered catamaran boat. Our steering mechanismincorporates the use of handlebars and has a bellcrank linkageassociated therewith so that full rudder control may be had in arelatively short handlebar turning radius.

Another object of the invention is to provide a uniquely constructedpermanently attachable foldable boarding ladder for use with powered skiboats and the like.

Other and further objects of the invention, together with the featuresof novelty appurtenant thereto, will appear in the course of thefollowing description.

DETAILED DESCRIPTION OF THE INVENTION In the accompanying drawings,which form a part of the specification, and are to be read inconjunction therewith, and in which like reference numerals indicatelike parts in the various views:

FIG. 1 is a top plan view of a catamaran power boat embodying theinvention;

FIG 2 is a bottom plan view of same;

FIG. 3 is a side elevational view of same;

FIG. 4 is a front elevational view of same;

FIG. 5 is a rear elevational view of same;

FIG. 6 is a schematic diagram showing the hydraulic circuit used tooperate the associated trim tabs;

FIG. 7 is an enlarged rear elevation view taken generally along the line7-7 of FIG. 3 in the direction of the arrows and showing the boardingladder located at the left rear external portion of the catamaran powerboat;

FIG. 8 is a sectional view taken along the line 88 of FIG. 5 in thedirection of the arrows with the broken line portion used to show theladder in its folded-down position;

FIG. 9 is an enlarged sectional view taken generally along the line 99of FIG. 5 in the direction of the arrow and showing motor fairing inelevation; and

FIG. 10 is a diagrammatic view of the steering linkage utilized in thecatamaran power boat.

Turning now more particularly to the drawings illustrating the poweredcatamaran, FIGS. 1 through 5 show the basic structure utilized in ourdevice. As seen therein, the catamaran has two identically shapedparallel hulls I0 and 11 which are interconnected by a substantiallyflat deck 12. Deck 12 extends from its forward end 12a toward the aftportion of the boat (transom I22) and has a dished-out motor well whichis generally represented by the numeral 12b.

Each of the hulls I0 and II has a keel line running longitudinally thelength thereof. As shown in FIGS. 2 and 3, there is a substantiallyvertical step 13 located in each hull. This step 13 occupies a positionwhich is approximately one-third of the entire length of the hull fromthe aft portion of same. The forward portion of each hull from step 13is more sharply angled away from the keel line to the vertical sides ofsame, than is the rear approximately one-third of each hull. To betterfacilitate forward movement through the water, each hull is contoured atits forward end extremity to present a reduced area, gradually enlargingsurface relative to the direction of movement of the boat. A keel plate14 is attached to the step area of each hull be means ofa bracket 14awhich is bolted or otherwise conventionally affixed to each hull at theabovementioned area. The keel plate extends both forwardly of the stepand rearwardly thereof so that inadvertent sliding of the craft duringsharp turns or drifting is obviated. In this manner the entire craft isstabilized during operation.

Continuing on with the discussion of the under side of the boat, motorwell 12b is contoured upwardly in a gradual arc from transom 12c tointegrally connect with the under surface of deck 12. The lower surfaceof well 12b has motor fairing l5 fixedly connected thereto andpositioned directly forward of the motors (M) propeller P whichoperatively propells the boat. The motor fairing is somewhatwedge-shaped (see FIGS.

2 and 3) with the vertex forward so that the water and associatedturbulence due to the movement of the boat is forced away from themotor's shaft housing. In this manner, the shaft housing flowsrelatively smooth through the water without the normal drag thereonwhich would otherwise be directed to the motor shaft and propeller.

Turning now to the upper side of deck 12, a straddle pedestal-typeseating structure is substantially centered on the fore-aft center lineof the deck and has approximately four seats thereon. (The seatingcapacity could be either increased or decrease depending upon the sizeof the boat and the need for a certain number of available seats.) Theforward portion of the straddle pedestal seat construction (hereinafteridentified by the numeral 16) contains an operators console 160 withmotorcycle-type handlebars 17 extending upwardly therefrom andpositioned for optimum control by the person operating the boat andsitting in the forwardmost seat. The rear seat on the seating pedestal16b may be swivel mounted so that same may be rotated for the purpose ofobserving water skiers which are being towed by the boat. Finally, theentire mounting pedestal structure 16 may be hollow in nature with ahinged upper seat cushion portion so that the pedestal structure willserve as a storage facility.

Remotely controllable recessed lights 18 are located near the forwardportion of the deck as shown in FIGS. l and 3 and are convenientlyoperated so that they may be either drawn within deck 12 so as todisappear completely or hingedly swung upwardly (see FIG. 3) so thateach light directs an illuminating beam above and forwardly of the boat.

The hulls rearward surfaces adjacent transom 120 have trim tabs 19mounted thereon. As clearly seen in FIGS. and 6, each hull l0 and 1 1has a separate but mutually controllable trim tab hingedly connectedthereon slightly above the lower surface of same. Each of the trim tabs19 has a hydraulic cylinder 20 associated therewith which includes theconventional extendable piston 20a. Piston 20a is interconnected withits associated tab at its clevised end 20b by pivotally engaging asuitable upturned bracket thereon. Each hydraulic cylinder may besuitably affixed to the transom 12c of the boat by any suitableconventional bracket means.

The hydraulic circuit depicted in FIG. 6 may be utilized to positionboth trim tabs at the desired location. For instance, the foot pedal 21is mechanically linked to a reservoir piston 22, same being reciprocallymovable within the hydraulic reservoir 23. A single depression of footpedal 21 results in a high pressure through check valve 24 and throughline 24a to each hydraulic cylinder 20. This high pressure conditionextends pistons 20a so that the trim tabs 19 are moved to position 19a(see FIG. 6). The tabs will stay in this position 19a until the pedal ispumped again. Another rapid depression of the foot pedal 21 moves thetrim tabs down to position 1% and a final pumping of pedal 21 will movethe tabs to the position of 19c in a manner similar to that describedabove with a reference to position 19a. When the operator removes hisfoot from pedal 21, the normal resistance to the forward movement of theboat will move the trim tabs back to their horizontal positions (shownin solid lines in FIG. 6) with the oil flow being regulated through thevalve 25 via line 25a. As suggested above, it is contemplated that thepedal 21b is springbiased in any conventional manner so as to assist inthe movement of piston 22 to its upper position when the pedal is notbeing manually depressed. This condition permits the equalizing oil flowthrough valve 25 back to reservoir 23.

With the trim tabs so conveniently controllable in the manner describedabove, the proper planing attitude of the boat is quickly obtainablewhen pulling water skiers up out of the water into a skiing position.For example, with a number of skiers in the water awaiting to be towed,the boat motor M is usually idling. In this condition, the aft portionof the hulls are also in the water. To achieve maximum efficiency ofmotor M with our boat, when the throttle is opened and the forward gearengaged, it is necessary that the forward movement of the boat beaccomplished with only the hull portions forward of step 13 in contactwith the water. By lowering the tabs 19 to a water contacting position(either 19a, 1917 or the boat is forced onto the forward hull portionsthereby reducing the skin frictioned resistance to boat propulsion.Since there are three different trim tab water contacting positions, theboat operator may select the appropriate position depending on the towedload (e.g. the water skiers) thereby obtaining the optimum boat planingattitude with a minimum power and time requirement. Furthermore, oncethe boat attitude has been obtained, the air flow between the hulls(with its associated airfoil effect) and the hull shape cause thefrictional drag of the water on the hulls to be reduced so that highspeeds, stability and maneuverability are simultaneously available.

To further facilitate the full and convenient use of our boat, we havedesigned a uniquely constructed permanently attached fold down boardingladder which is shown in detail in FIGS. 7 and 8. The ladder issupported from two parallel side members represented, by the numeral 26,which may be fixedly attached to the transom 12c by conventional boltsor woodscrews. The lower end portions of each of the side members issuitably apertured with a rod member 27 rigidly anchored therebetween. Apair of rotatable brackets 28 are located on rod member 27, there beingone bracket adjacent the inner opposed sides of each of side members 26.To facilitate assembly, the brackets are centrally apertured in thecircular portions thereof and conveniently sized so that when same hasthe rod member extending through the apertures, the brackets may beconveniently swung either up or down respect to fixed rod member 27 and,as will be seen, through an arc determined by the outer peripheral edgeof the circular portions of the brackets. Tubular bars 29 are weldedlyattached to one surface of brackets 28 and 29a and extend tangentiallyaway from rod 27. Step rungs 30 and 31 are likewise welded transverse tothe upper and lower end extremities of the tubular bars 29. A circularcontacting rod 32 is weldedly connected to the inner surface of rod 27so that same is located between rod 27 and transom 12c and which may beused to operatively position the ladder either in its unfolded or storedposition.

In operation, FIG. 7 shows the ladder folded up as it would be in thecase when the boat is moving with or without skiers being towed fromsame. The solid line portions of the ladder in FIG. 8 indicate that whensame is folded up, the upper ladder rung 31 contacts the upper surfaceof contacting rod 32. When the ladder is folded down to facilitate aswimmer or skier boarding the boat, the lower rung 30 will be swung in acounterclockwise direction (as shown in FIG. 8) so that a projectingcontact lug 28a, which forms a portion of bracket 28a, swings to theunderside of contacting lug 32 and abuts same with its new uppersurface. In this manner, the ladder structure will quite easily supportone seeking to board the boat with the entire unitary structure beingbraced against itself and with rungs 30 and 31 optimally located tofacilitate the normal boarding procedure. Of course, when the ladder isno longer needed, it may be manually moved to the solid line positionshown in FIGS. 7 and 8 or the forward movement of the power boat willlikewise swing an extended ladder in a clockwise (FIG. 8) or folded upposition. In this manner, the ladder is maintained conveniently out ofthe way when not needed, yet, is permanently attached to the boat andwill not be lost overboard or mislaid when it is needed.

We have found that the seating facility (pedestal seating structure 16)offers several advantages over the conventional cavity-type seating in amonohull boat. For instance, the operator and observer are up above thewater surface with the operator located at the forward portion of theboat rather than at the rear. Likewise, with the trim tabs reacting soas to quickly locate the boat in its planing attitude (that being on theforward two-thirds portion of each hull) and with the normal runningattitude being with the bow or forward portion of the boat in arelatively horizontal plane, the vision of the operator is not obscuredby a raised bow as so often happens with monohull crafts and similarstructures.

Not the least of the inherent advantages to the power boat describedabove is the motorcycle-type steering mechanism of which handlebar 17forms an integral part thereof. FIG. schematically shows our steeringlinkage which has particular utility with the catamaran disclosedimmediately above. For instance, the steering column (not shown) is, ofcourse, movable with the handlebars and has a first bellcrank 33attached thereto so that it is movable in accordance with the moving ofhandlebar 17. The end portion of the bellcrank has shaft 34 connectedthereto and which operates to translate handlebars movement to the rearportion of the boat and more particularly to a second pivotally mountedbellcrank 35. Bell crank 35 may be mounted on a pivotal mount 35a in anyconvenient and conventional manner, however, the rearwardly turnedportion of bellcrank 35a will include a rod 36 weldedly attached theretowith rollers 36a and 36b affixed to each end portion thereof.

As is common with most power boats, the motor M of our powered catamaranis utilized as a steering rudder as well as a means to propel the boat.In this manner, the motor is conventionally swivelly mounted on thetransom and will have an endless steering cable 37 affixed to theforward portion thereof. Cable 37 is supported in a substantiallyhorizontal plane by rollers 37a and is under sufficient tension so thatthe cable is not permitted to droop. Likewise, the forward rollers 37asupport the cable 37 in contact with rollers 36a and 3612 which, assuggested above, are movable with bellcrank 35. In this manner, whenhandle bar 17 is rotated, its rotative movement is translated frombellcrank 33 via rod 34 to bellcrank 35 and onto the rod 36. Since rod36 extends substantially parallel to cable 37 when the boat is steeredalong its lubber line or straight ahead (see FIG. 10), a movement of thehandlebar either to the right or the left will accordingly swing rollers36a and 36b, respectively, into contact with cable 37 thusly pivotingmotor M in its proper direction to facilitate the steering of the boat.As shown in FIG. 10, when handlebar 17 is turned to the right, bellcrank35 is moved about its pivot pin 35a to the broken line position (in acounterclockwise direction). The arcuate movement of bellcrank 35 swingsthe upper roller 36a against steering cable 37 moving same inwardly anddownwardly within the perimeter of the endless steering cable loop.This, of course, swivels motor M in a counterclockwise direction andresulting in the boat being steered to the right. With the rod arm 36adding additional leverage onto the movement of cable 37, it is notnecessary to move handlebar 17 so dramatically in order to negotiatesimple turns either to the right or to the left, thusly cooperating withthe stability features of the boat design to result in an extremelymaneuverable craft.

From the foregoing, it will be seen that this invention is one welladapted to attain all of the ends and objects hereinabove set forthtogether with other advantages which are obvious and which are inherentto the structure.

It will be understood that certain features and subcombinations areutility and may be employed without reference to other features andsubcombinations. This is contemplated by and is within the scope of theclaims.

As many possible embodiments may be made of the invention withoutdeparting from the scope thereof, it is to be understood that all matterherein set forth or shown in the accompanying drawings is to beinterpreted as illustrative and not in a limiting sense.

Having thus described our invention, We claim:

1. A boat having two spaced apart hulls interconnected by asubstantially flat deck, said boat comprising:

at least one seating means substantially centered along the longitudinalcenter line of said deck, said seating means extending above thehorizontal plane of said deck and adaptable to be straddled, said hullseach having a substantially vertical step therein at a locationapproximately one-third of the length of said hulls, said step dividingthe lower surface of each hull into two adjacent surfaces lying insubstantially parallel planes, and means for facilitating the movementof said hulls from an attitude where both adjacent surfaces contact thewater to a planing position with substantially only that portion of saidhulls forward of said step in said water contacting position.

2. The invention as in claim 1, wherein said boat includes a motormounted on same, same being operable to propel said boat through thewater, and means for protecting sad motor from turbulence as said boatis being propelled.

3. The invention as in claim 2, wherein said boat includes a motor welllocated adjacent the aft portion of same and wherein said protectingmeans includes a motor fairing interconnected with said motor well andpositioned forwardly of the location normally occupied by said motor.

4. The invention as in claim 2, wherein said boat includes a handlebarsteering mechanism located at the forward end portion of said seatingmeans, said handlebar interconnected by a mechanical linkage with saidmotor and operable to position said motor for steering purposes inaccordance with the movement of said handlebar mechanism, said motorlinkage including a means for facilitating the control of the steeringmovement of said motor so that relatively short ratio turns of saidhandlebar steering mechanism positively controls the steering movementof said motor.

5. The invention as in claim 4, wherein said linkage between said motorand said handlebar steering mechanism includes a bellcrank pivotallymovable in accordance with the movement of said handlebar steeringmechanism, a steering cable interconnected with said motor, a rod meansinterconnected with said bellcrank and contacting said steering cable toeffect the movement of said steering cable and said motor with themovement of said bellcrank.

6. The invention as in claim I, wherein said hull planing means includesat least one trim tab hingedly connected to said boat and hydraulicmeans for positioning sad trim tab in an optimum position to move saidboat onto the forward planing surfaces of said hulls.

7. The invention as in claim 6, wherein said boat includes at least onetrim tab adjacent the rear end extremity of each of said hulls, andwherein said hydraulic means has a foot pedal located adjacent saidseating means, said foot pedal operable to operate a hydraulic ramassociated with each trim tab in accordance with the position of saidfoot: pedal.

8. The invention as in claim 7, wherein said trim tabs are movable toany water contacting operating position each time said foot pedal isfully depressed, said trim tabs having three operable water contactingpositions, each of which results in the movement of said boat to theforward hull planing position.

9. The invention as in claim 1, wherein said boat includes a keel platelocated at each step position of said hulls said keel plate operable toobviate sliding of the boat as the turns are negotiated or to maintain asteady course with minimum drift.

10. The invention as in claim 1, wherein said boat includes a foldableladder fixedly attached to same, said ladder including a horizontal rodfixedly attached to said boat, at least two brackets pivotally attachedto said rod, said brackets having at least two contacting surfaceswherein one of said surfaces contacts a contacting rod fixedly attached!to said first mentioned rod when in a folded-up condition and said otherof said contacting surfaces contacting the lower portion of saidcontacting rod when in a folded-down position.

1. A boat having two spaced apart hulls interconnected by asubstantially flat deck, said boat comprising: at least one seatingmeans substantially centered along the longitudinal center line of saiddeck, said seating means extending above the horizontal plane of saiddeck and adaptable to be straddled, said hulls each having asubstantially vertical step therein at a location approximatelyone-third of the length of said hulls, said step dividing the lowersurface of each hull into two adjacent surfaces lying in substantiallyparallel planes, and means for facilitating the movement of said hullsfrom an attitude where both adjacent surfaces contact the water to aplaning position with substantially only that portion of said hullsforward of said step in said water contacting position.
 2. The inventionas in claim 1, wherein said boat includes a motor mounted on same, samebeing operable to propel said boat through the water, and means forprotecting sad motor from turbulence as said boat is being propelled. 3.The invention as in claim 2, wherein said boat includes a motor welllocated adjacent the aft portion of same and wherein said protectingmeans includes a motor fairing interconnected with said motor well andpositioned forwardly of the location normally occupied by said motor. 4.The invention as in claim 2, wherein said boat includes a handlebarsteering mechanism located at the forward end portion of said seatingmeans, said handlebar interconnected by a mechanical linkage with saidmotor and operable to position said motor for steering purposes inaccordance with the movement of said handlebar mechanism, said motorlinkage including a means for facilitating the control of the steeringmovement of said motor so that relatively short ratio turns of saidhandlebar steering mechanism positively controls the steering movementof said motor.
 5. The invention as in claim 4, wherein said linkagebetween said motor and said handlebar steering mechanism includes abellcrank pivotally movable in accordance with the movement of saidhandlebar steering mechanism, a steering cable interconnected with saidmotor, a rod means interconnected with said bellcrank and contactingsaid steering cable to efFect the movement of said steering cable andsaid motor with the movement of said bellcrank.
 6. The invention as inclaim 1, wherein said hull planing means includes at least one trim tabhingedly connected to said boat and hydraulic means for positioning sadtrim tab in an optimum position to move said boat onto the forwardplaning surfaces of said hulls.
 7. The invention as in claim 6, whereinsaid boat includes at least one trim tab adjacent the rear end extremityof each of said hulls, and wherein said hydraulic means has a foot pedallocated adjacent said seating means, said foot pedal operable to operatea hydraulic ram associated with each trim tab in accordance with theposition of said foot pedal.
 8. The invention as in claim 7, whereinsaid trim tabs are movable to any water contacting operating positioneach time said foot pedal is fully depressed, said trim tabs havingthree operable water contacting positions, each of which results in themovement of said boat to the forward hull planing position.
 9. Theinvention as in claim 1, wherein said boat includes a keel plate locatedat each step position of said hulls said keel plate operable to obviatesliding of the boat as the turns are negotiated or to maintain a steadycourse with minimum drift.
 10. The invention as in claim 1, wherein saidboat includes a foldable ladder fixedly attached to same, said ladderincluding a horizontal rod fixedly attached to said boat, at least twobrackets pivotally attached to said rod, said brackets having at leasttwo contacting surfaces wherein one of said surfaces contacts acontacting rod fixedly attached to said first mentioned rod when in afolded-up condition and said other of said contacting surfacescontacting the lower portion of said contacting rod when in afolded-down position.